Level encoding in the AN and CN of hearing-impaired

描述(申请人提供)：拟进行的神经生理学实验 是由音级编码的两个基本方面驱动的，这两个方面是 受耳蜗性损伤的严重影响，目前提供了显著的 有效助听器设计面临的挑战。(1)响度招募 中出现的减小的动态范围和异常响度增长 几乎所有听力受损的人都有耳蜗病。人们通常认为 这种响度与声音引起的总的神经活动有关； 然而，在正常和受损的情况下，这种关系的性质仍然不清楚 耳朵。一个目标是系统地描述神经活动的增长 随着听觉神经(AN)纤维群体中刺激水平的增加， 正常和听力受损的猫。刺激是基于典型的心理物理的 测量响度招募的研究，包括音调、宽带噪声、 讲话和蒙面的语气。(2)复杂声学的稳健谱形状编码 刺激是许多基本听觉功能所必需的 沟通。语音表示的显著增强具有 在耳蜗核向耳蜗核的转化过程中，已有报道。 听力正常的动物。第二个目标是比较频谱形状编码在 正常猫和听力受损猫的CN。将使用两种方法来 评估编码光谱形状的相对水平敏感度 腹侧核的不同细胞类型。收集到的数据将改善 了解耳蜗损伤如何影响声音的神经表征， 并将为设计新的助听器策略提供有用的信息 在保持和增强频谱的同时克服响度恢复 代表权。

DESCRIPTION (provided by applicant): The proposed neurophysiological experiments are motivated by two fundamental aspects of sound-level encoding that are strongly affected by cochlear damage and that currently provide significant challenges for the design of effective hearing aids. (1) Loudness recruitment represents the reduced dynamic range and abnormal loudness growth present in almost all hearing-impaired persons with cochlear damage. It is often assumed that loudness is related to the total neural activity evoked by a sound; however, the nature of this relation remains unclear in normal and impaired ears. One aim is to systematically characterize the growth of neural activity with increasing stimulus level in a population of auditory-nerve (AN) fibers for normal and hearing-impaired cats. Stimuli are based on typical psychophysical studies that measure loudness recruitment, and include tones, broadband noise, speech, and masked tones. (2) Robust spectral-shape encoding of complex acoustic stimuli is necessary for many basic auditory functions that underlie communication. A significant enhancement in the representation of speech has been reported in the transformation from the AN to the cochlear nucleus (CN) in normal-hearing animals. The second aim is to compare spectral-shape encoding in the CN of normal and hearing- impaired cats. Two methods will be used to evaluate the relative-level sensitivity for encoding spectral shape in the different cell types of the ventral CN. The data collected will improve the understanding of how cochlear damage affects the neural representation of sound, and will provide useful information for the design of new hearing-aid strategies to overcome loudness recruitment while maintaining and enhancing spectral representation.